Morpholine complexes of mercury (II) halides

=~IORG.

NUCL.

C1{. M,

LETTERS

Vol.

5,

pp.

255-258,

1969.

Fergomo.

Pre=s.

Printed

in

Oreat

8fitaln

I.S. Ahuja & (Miss) P. Rastegi Chemistry Department, Ba~ara~ Hindu University, Bamaras - 5 (ladia). (Received 30 December 1968, in revised form 30 Januoey 1969)

Recent spectroscepio studies en the cemplexes of morpheline with the halides and sulphates ef ~anganese(ll),

cebalt(ll), oepper(ll), zinc(II)

and cadmium(ll) have shewn that the merphelins is ceerdinated te these metals threugh nitregen (1,2).

The present ce~-,~unicatien describes such studies en

the merpheline cemplexes with mercury~ II) halides. The cemplexes prepared, their analytical data and the extracteC i.r. spectra are listed in Table I. the bismerphelinemercury(II)

The menemerphelinemercu~y(ll)

chlerAde and

bremide were prepared by adding merpheline te the

respective mercury(II) halide selutien in ethamel.

The bismerphelinemercury(II)

chleride was ebtaine~ by adding merpheline te mercury(If) chleride selutien in ether.

The iede- complex was prepared by heating mercury(if) iedide with

an excess ef morpheline!

the cemplex which crystallized eut en oeeling was

filtered and washed with dry ether. The i.r. spectra in the reck salt regien were recerded as Nujel and hexaehlerebutadiene mulls supperted between sedium ohleride plates en a Hilger H-800 spectrephetemeter.

The far i.r. spectra (15 te 45 ~) were recerded as

liujel mulls supperted between thin polythene sheets en a Orubb Farsens' D M4 spectrophntometer fitted with caesium iodice eptics. ~'he reck salt regien i.r. spectra e~ all the mercury []I) halide morpholine

complexes ~hn~ that the N - H stretchinc vibratien occurs at lewer

frequencies than in the unceordinated morpheline thus explaining the electren drainage from the nitregen due te its oeordinatien te the metal atem [i - 3). 255

256

MORPHOLINE COMPLEXES

Low values indicate

of the molar

o~ductanoe

that the complexes

non-ionic.

However

halide

er I! and L = a menedentate

are nen-electroiytes

complexes nitrogen

Although bisnorphelinemercury(Ii) solutions

by earlier workers

merpholinemercury(ll)

weight

pressure

and the halide

atems are

of the type HgL2X 2 [where X = CI~ Br ligaad)

are u s u a l l y pseude-tetrahe~ral. been prepared

the present

stuuies

li~unds

to oe dimer~c

I rem alcoholic

snow that the mone-

osmometer

tetrahsdral

in the trams- positions

el" the menomorphclinemercury(]I)

Inc. vapour

for these complexes

is obtainea uncer such c o n d i t i o n .

oeen s n o ~

and the organic

selutiens

they appear as i:I electrolytes.

chieride has

(4,5)

chloride

ef t~e type h g L X 2 nave bridges

in alcehelio

in dimethylformamide

1~e meroury(ll)

Vol. 5, No. 4.

model

chloride

~Tith halogen

(6,().

determinea

3(~I A, u s i n g di~lyme

~;omplexes

I:iolecular

en a l~ecnrelab

as a solvent

is 4b~

theoretical: while

H g ( m o r p h o l i n e ) C 1 2 = 358 ; ~{g(merpheline)C12 + diglyme = 4~2 ) L CI • C1 the dimeric ~llg ~ ~ Hg ~ molecule requires 716. ('l~e C1 C1 L

mol~cular B.H.U.

weight

determination

te whom thanks

mercury(II)

chloride

are due).

and osh~ves

coin E occupied chlori0e

carried out by kr. V.~. kuley, l~icreanalyst,

It is thus

may be either dimeric

solid state Out in solution di~lyme,

was

it appears

as a monomoric

by the solvent

were actually

t~o soI't o~ vib L'a~tions Lot the

tetrahedral

tha~ t'~ monomorpholineor 3-ceo~dinate

to t~n_ke up a molecule

molecule

molecule).

~imeric

considered

tetra~edr~l

[the fourth

in the

o± the selvent~

coordination

position

If the monoz!orpholineme1"cury[I!) in the soli~ o~ate

H g - 'D1 stretch~n~

modes

one ~rould exoect

(6) --

one a t / 3 2 0

-

290 cm -I due te terminal H g - C1 and toe other w2([~9 cm -1 aue te briaginc K g - C1 greup~

~hile only one ~ 3 2 0

linemercury(I~)

chloride.

- "290 ~

;~he appearance

-I for the te~ro_~ecLral b i s m o r p h e of a strong absorption

306 cm -I in the mono- as well as in bis - morpholine~ercury[Ii) indicate

that the former

of such absorption further

confirms

is dimerio

tetr~~hedral

chloride

in the solid state.

bounds in the bismorphelinemercury(II)

the assignment

band at

bromide

The absence

and ioaide

~I the bound at 3(~6 om -i due to zerminal Hg - C1

Vol. 5, No. 4.

MORPHOLINE COMPLEXE S

257

mode aria is in fair &greemant with the frequency normally abseciated with tstrahedral mercury - chlorine modes (6). bridging) expected ~ 2 0 0

The ether Hg - Cl made ~due te C1

cm -i as well as the terminal hg - Br amd Hg - I medea

are below the range (222 om -i) of the spectrophotemeter used in the present investigations. The low frequency i.r. spectra of all the mercury (I~) halide complexes absorb strongly at ~ 3 ~ 0 om

-I

which is net observed in the free merpholine. TABL~

I

)felting Analytical Data ~xtracted i.r. spect~& peint, i~xperimental Calculated iall figures in cm -~) aC. Netal Halogen Netal aalogen

Cempetmd

~

~

~

N - H Pmssible stretch k - N mode

Metal~alegen

mede

Nerpholine

3440s

H~merpheline)Cl 2

152

55.8

19.6

55.9

19.b

3190~

353 a

306 a

H~merpholine)2Cl 2

138 d

45.8

15.7

44.9

15.9

3188 m

340 s

3@6 a

Hg(merpheline)2Br 2

128

38.0

29.3

37.5

29.9

3300 s

335 s

..

H g ( m e r p h o l i n e ) 2 12

132 d

32.6

..

31.8

..

3274 s

340 s 320 s

..

* = ieCine could net be estimated~

s = strong;

m = medium;

]~:orpholine itself gives ~eaks in the far i.r. near 580, 43~ aria 258 cm -1 and the coordin~tted merpheline aAso gives peaks in these regions.

These peaks are

common to all complexes and have been omittea from toe Table.

'It is suggestea that these bands a~e most probably d~e to mercury(ll~ - nitrogen modes.

These bands eccur at almost the same frequencies f®r chlere-, bromo-

and lode- com-lexes.

This is to be expected for the metal - nitrogen modes in

the absence of s ~ n i f i c a n t in this

couplin F with metal - halogen modes.

Similar bands

r~n~e have 0sen observed ant assignea to ~ - i~ meaes in the halide

258

MORFHOLINE COMPLEXES

and sulphate oemplexes

(1,2).

1~rthermore,

Hg - N modes seems reasonable as absorptions

Vol. 5, No. 4.

the allocatlen o f these bands to in this range have been allocated

te Hg - N modes in most other mercury [II) complexes (9,10).

'i~e authors express ~ e i r

sincere thanks to Prof. G.B. Singh, Head of t~e

Chemistry Departmen~ for providing necessary facilities, te Dr. I.S. Sing~, Reader~ Spectroscopy

Department,

qlha~qs are also due

B.~.~ . for help in recording

the reck salt rs~ien i,r. spectra; M/s. ~lilger & Watts~ London for the far i.r. spectra an~ the U.(~.C. for the ~ward of a fellowship (~lisB Rastegi).

i.

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R.C. EVANS, F.G. ~J%NN, H.S. PEI[~ER and D. PURDIE,

J. Chem. ~ec., 1209 (1940)

7.

R.C. CASS, O.~. C O A T ~ R.G. RAPIDER ~

and

J. Chem. ~ec., 4007 (1955)

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G.J~. COAL ;~ and D. RIDL~;~

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K. NAKA}i(~PO,

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T.J. LA1fT~_: a~qd

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